Boiler



Oct. 15, 1929. w. M. KEENAN 1,731,577

BOILER Filed Sept. 26, 1927 2 Sheets-Sheet 1 INVENTOR B M /Z ;r; A TTORNEY Patented Oct. 15, 1929 UNITED STATES PATENT; oFFicr.

WALTER M. KEENAN, OF NEW YORK, N. Y., ASSIGNOR TO THOMAS E. MURRAY, OF

BROOKLYN, NEW YORK BOILER Application filed September 26, 1927.

My invention aims to provide certain improvements in boilers applicable especially but not solely to boilers of the marine type.

The accompanying drawings illustrate an embodiment of the invention.

Fig. 1 is a front elevation of the steam generating elements;

Fig. 2 is a side elevation partly in section;

Fig. 3 is a cross-section on the line 33 of Fig. 2.

The principal elements of a boiler of this type are the banks 1 of water tubes at opposite sides extending from drums 2 at the sides obliquely upward to the central steam drum 3. The boiler is generally fired by means of oil burners 4. Or coal dust firing or other firing methods may be used.

The burners are located in the front end of the boiler and project the flame into the triangular space between the groups of tubes 1, the hot gases passing through the spaces between these tubes and out to the stack. Any usual or suitable style of casing, baffles, and so forth, may be used.

The invention provides for an increase of the capacity of such boilers and for other ad vantages by a simple addition of supplementary water tubes.

I provide a back wall of vertical water tubes 5 which may constitute substantially the whole back wall or may be in efiect a lining for a casing at the back. Such a water wall would be very durable and would save a considerable expense 110w involved in renewals and repairs.

In addition there is provided an approximately horizontal group of water tubes 6 across the bottom of the combustion chamber which cool the ashes so as to prevent their falling in molten condition into the ash pit 7 These tubes 6 are slightly inclined upward at the rear and are continuous with the tubes 5 of the back wall. The tubes 5 and 6 are exposed directly to the radiant heat of the burning fuel and have, therefore, very large steam generating capacity. By making these tubes continuous across the bottom and back, lightness and simplicity are secured, features which are particularly desirable in marine practice.

Serial No. 221,869.

A bottom header 8 for these tubes extends across the front of the furnace located in a casing or box 9 in the lower part of the front walllO. A top header 11 extends across the back below the steam drum and is connected at intervals in its length to the latter by means of anumber of pipes 12. Fromthe lower part of the front end of the steam drum, down-going pipes 13 convey the water from the steam drum to the lower header 8. These pipes enter opposite ends of the header 8 and are located outside of the boiler where they are comparatively cool so as to induce a rapid circulation. The exposure of the supplementary tubes 5 and 6 to radiant heat requires easy and rapid circulation in order to protect them from excessive heating and at the same time to make the fullest use of their steam generating capacity. lhese results are achieved in the simplest fashion by the bottom and top headers with the two sets of tubes extending continuously between them and the direct connections from the top header to the steam drum and from the latter to the bottom header.

F or the tubes of the rear wall, I prefer to use the type shown in Fig. 3 provided with fins 14 which extend into the spaces between them and preferably overlap or substantially abut so as to fill such spaces. These fins increase the protection of the rear wall against excessive heating and also provide an in-- creased area exposed to the radiant heat so as to make the most effective utilization thereof.

The front of the boiler may be of the ordinary type or may be provided in addition with a water wall similar to that at the back, with a further increase of capacity.

While I prefer to expose the naked tubes at the bottom and at the back of the combustion chamber to the direct radiant heat of the burning fuel, they may be shielded from the same to a greater or less extent and still utilize such radiant heat.

Various modifications may be made by those skilled in the art without departing from the invention as defined in the following claims.

What I claim is:

1. A boiler of the marine type having a central steam drum at the top, parallel drums at the sides and tubes extending upward from such side drums to the central steam drum, a lower header extending transversely across the bottom of the front or firing end of the boiler, an upper header extending across the top of the rear end, continuous tubes extending horizontally from the lower header to the rear and thence upward to the upper header, pipes leading from the front end of the steam drum to the lower header and pipes leading from the upper header to the rear end of the steam drum.

A boiler of the marine type having a central steam drum at the top, parallel drums at the sides and tubes extending upward from such. side drums to the central steam drum a lower header extending transversely across the bottom of the front or firing end of the boiler, an upper header extending across the top of the rear end, continuous tubes extending horizontally from the lower header to the rear and thence upward to the upper header, pipes leading from the front end oil the steam drum to the lower header and pipes leading from the upper header to the rear end of the steam drum, the tubes between said headers being spaced apart throughout their horizontal portions and having lateral extensions between them along their upright portions.

In Witness whereof, I have hereunto signed my name.

l/VALTER M. KEENAN. 

